Fixed erroneously commented-out \end{itemize}
Fixed erroneously commented-out \end{itemize}

Commit 4cb61407a8bbd6050e876995f149b07cf9299445, CL
https://codereview.chromium.org/2476613002 introduced a spurious `%`
which causes `latex dartLangSpec.tex` to fail. This CL fixes it.

Review URL: https://codereview.chromium.org/2487113003 .

dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk